What emblems were used? Although noting
that Jesus had used wine during the Lord’s Supper,
for a time the Watch Tower recommended instead
the juice of fresh grapes or cooked raisins,
so as not to tempt those “weak in the flesh.” However,
wine was provided for those who felt that
“fermented wine was meant to be used.” The Bible
Students later understood that unadulterated
red wine is the proper symbol of Jesus’ blood.
The above quote from the magazine is blaming the 'Watchtower' for it's incorrect understanding. It wasn't the fault of the faithful & discreet slave at all.